ISLAMABAD , (DNA) – Pakistan was in shock on Saturday after a suicide blast killed 131 people, shaking confidence in security just as the dramatic arrest of ex-prime minister Nawaz Sharif ratcheted political tensions higher ahead of nationwide polls.

Sharif s dramatic return from London and subsequent arrest for corruption was overshadowed as the carnage in Mastung, in the country s southwestern province of Balochistan, unfolded late Friday.

Newspapers branded the blast — one of the deadliest in Pakistan s history — a “massacre”, as analysts and media called on the military to,  “do the job they are meant to do — ie preventing attacks”.

One week ago, Sharif was sentenced in abstentia to 10 years in prison on corruption charges. He was transferred to the garrison city of Rawalpindi, adjacent to Islamabad, after landing in Lahore Friday. Media reports said he was being held in a prison there.